Association Between Timing of Extracorporeal Membrane Oxygenation and Clinical Outcomes in Refractory Cardiogenic Shock

Objectives: The aim of this study was to investigate whether earlier extracorporeal membrane oxygenation (ECMO) support is associated with improved clinical outcomes in patients with refractory cardiogenic shock (CS). Background: The prognosis of patients with refractory CS receiving ECMO remains poor. However, little is known about the association between the timing of ECMO implantation and clinical outcomes in these patients. Methods: From a multicenter registry, 362 patients with refractory CS who underwent ECMO between January 2014 and December 2018 were identified. Participants were classified into 3 groups according to tertiles of shock-to-ECMO time (early, intermediate, and late ECMO). Inverse probability of treatment weighting was conducted to adjust for baseline differences among the groups, followed by a weighted Cox proportional hazards regression analysis to calculate hazard ratios and 95% confidence intervals for 30-day mortality associated with each ECMO time group. Results: The overall 30-day mortality rate was 40.9%. The risk for 30-day mortality was lower in the early group than in the late group (hazard ratio: 0.53; 95% confidence interval: 0.28 to 0.99). Early ECMO support was also associated with lower risk for in-hospital mortality, ECMO weaning failure, composite of all-cause mortality or rehospitalization for heart failure at 1 year, all-cause mortality at 1 year, and poor neurological outcome at discharge. However, the incidence of adverse events, including stroke, limb ischemia, ECMO-site bleeding, and gastrointestinal bleeding, did not differ significantly among the groups. Conclusions: Earlier ECMO support was associated with improved clinical outcomes in patients with refractory CS.